Hickory Substation Project Proposed by Denton Municipal Electric

Oct 10, 2014

Denton Municipal Electric (DME), Denton, Texaas, has identified several projects within the DME system that are critical to maintaining reliability and allowing Denton to continue to grow. An open house to inform the public about this project was held on September 30, 2014.

Reconstruction of the Hickory Substation is one project that is necessary. The work involved in this reconstruction is as follows:

Reconstruction of the existing Hickory Substation to accommodate upgrades from a 69-kV to 138-kV substation.

Rerouting of transmission and distribution lines into the new substation.

Retiring and removal of the equipment in the existing station.

The reconstruction of the Hickory Substation from 69 kV to 138 kV will require a larger footprint space. A minimum of 1.9 acres is needed to accommodate the upgraded 138-kV system equipment. If additional acreage is acquired it would allow for increased operational flexibility and future upgrades to handle increased electrical loads in the area. Several alternatives have been considered as possible locations for reconstruction of the Hickory Substation. A map is attached that shows location options that are currently being considered. A substation location could be chosen that is different from those locations shown on the map. All facilities will be owned and operated by DME.

There are three primary reasons that the station must be rebuilt. First, the capacities of the electrical bus (conductors), circuit breakers, and switches in the station are no longer adequate for the electrical flow that the station could experience. Second, DME is working toward conversion of the 69-kV transmission system to 138 kV in the 2017 timeframe. The existing Hickory station is only rated for 69-kV operation. The 138-kV equipment is larger, and conductor spacings must be greater because of the higher voltage. The larger equipment and spacing cannot be accommodated within the footprint of the existing equipment. Thirdly, stations that operate at 138 kV are configured differently than the configuration of the original construction to provide better flexibility and to meet additional performance standards. The revised station arrangement will require additional space.

Currently there is not adequate room within the existing substation site to make the needed upgrades. Additionally, it will not be possible to reconstruct the station on the existing site without extended outages that would have to last for several consecutive months at a time. The existing station equipment would have to be removed to make room for reconstruction because of conflicts between the new installation and the existing structures. Lengthy outages and the associated loss of capacity to serve the central area of the city are unacceptable reliability risks. Consequently, DME is opposed to use of the existing site for the reconstruction.

Following approval by the City Council of the proposed site, DME will undertake procurement of land for the proposed site. The time required for purchase of the land is unknown at this time. Design of the station will begin as soon as practical after it appears that land issues will be settled. DME would hope to have the new station in service during the spring of 2017.